Lawrence n



(No Model.)

L. N. 1?. POLAND.

DYNAMO ELECTRIC MACHINE.

Patented May 5,- 1891.

UNITED STATES PATENT OFFICE.

lLAVRENCE N. P. POLAND, OF CINCINNATI, OHIO.

'T-"DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 451,700, dated May 5, 1891.

Application filed May 7, 1888. Serial No. 273.060. (N0 model.)

To a/ZZ whom it may concern:

Beit known that I, LAWRENCE N. P. Po-

LAND, a citizen of the United States, and a resi- Electric Machines, of which the following is a specification.

My invention is an improvement in dynamo-electric machines.

It consists in the peculiar construction of the field-magnet, which insures greater rigidity, better magnetic contact, and enables the coils to be Wound separately and fixed upon the eld after being Wound.

It consists, also, in a peculiar construction of the armature-core and the wire for winding it and the commutators, by which space is saved and better ventilation secured.

It also consists of an automatic regulator whereby the electric current is regulated according to the duty required.

It iinally consists in certain details of construction and combinations of the several parts, all of which will be rst fully described in connection With the accompanying drawings, and then particularly referred to and pointed out in the claims.

Referring to the drawings, in which like parts are indicated by similar reference-Ietters Wherever they occur throughout the various Views, Figure 1 is a View taken transversely through the armature and its supporting-frame on line so a: of Fig. 3, showing the machine, except the armature and frame-rods, in end elevation. Fig. 2 is aperspective View, upon a reduced scale, of the hield-magnet core. Fig. 3 is a longitudinal central section of the armature and its supporting-frame, also upon a reduced scale, taken in line y y of Fig. 1. Fig. I is a transverse sectional View of the armature, taken in front of one of the Wire-supporting rings which is shown in elevation, except a portion which is broken out. Fig. 5 is a perspective View, upon a greatly-enlarged scale, of a portion of the ar mature-Wire. Fig. 6 is a detail view of the commutator.

The field-magnet A is cast in a single piece and has its poles reduced or beveled off. at a ce for convenience in slipping the previously- Wound coils B B over them. The magnet coils are wound upon collapsible cores of the same size as the parts of the magnet to be covered by them. The Wrapping is done in the following manner: Around the collapsible core is bent a thin sheet of Wood, Wood fiber, or other insulating material, and over each end of this are forced' brass plates b. The core is then clamped between centers of a lathe and the core revolved until the requisite amount of wire has been Wrapped around it. The core is then collapsed and removed, leaving the Wire coiled around the wooden shell between the plates b, which are upon each end. The coils so prepared are then pushed over the reduced poles of the field A until their ends are above the concave portions, after which the Whole is placed in a press and the coils forced to the position shown in Fig. I. The coils are securely held in place by brass rods b', which are passed through perforations in the field-core A.

The armature-shaft C has its bearings in yokes D, which are preferably of brass. Th ese yolres are united by rods d, the rods and yokes forming a frame to support the armature. The frame (with the armature and its shaft mounted in it) is held in position by four boxes D through which the rods d pass, which boxes are secured by bolts d upon the outside faces of the field-magnet A. By this means of securing the armature-frame to the field-magnet I am enabled to accurately adjust the armature in proper relation to the field at small expense and avoid the labor and uncertainty of accurately drilling through the poles of the field-magnet.

The armature-core consists of the longitudinally-grooved cylinder E, which may be of Wood ber or other suitable non-conducting material, the thin iron disks F, mounted upon this cylinder, the insulating rings or collars G, which are preferably formed of a number of paper Washersinterposed between the disks F to separate them the proper distance apart, and the iron clamping-collars H, which are screwed upon the threaded ends of the enlarged central portion of the armature-shaft C for the purpose of clamping the rings F and collars Gr together upon the cylinder E. The iron disks F are bored radially from their peripherie's to the central bore, as clearly shown at f, Fig. 4, and are also perforated from side IOT) to side through the radial perforations shown at f', same figure. The radial perforations meet the longitudinal grooves in the cylinder E, thus thoroughly Ventilating the armature and preventing heating when run at a high speed.

The Wire I, which is employed for winding the armature, is in cross-section a sector of a hollow cylinder, the inner diameter of which is the same as the armature-core and the ontside diameter slightly less than the bore of the field-magnet, as clearly shown in Figs. l and 5. The wire is wound with a ribbon of insulating material, as shown by diagonal lines, Fig. 5. This shape of wire allows the Whole armature-core to be covered without waste of space, as would be the case if the Wire were round or square. In winding the armature the wires are separated by wood or fiber plates or iiat pins t', secured in notches in the clamping-plates H.

The commutator consists of an iron spool J, having a permanent end or fiange j and a removable end j. The ends are beveled or dished upon their inner faces, so as to overhang the dovetailed ends of the commutatorbars K. The bars K have outward extensions lo, upon which the Wires l are secured. The bars are insulated from each other by asbestus and from the spool by fiber, vulcanite, or other non-conducting material. The bars K are clamped firmly upon the spool J by screwing up the endj.

I have shown the removable end of the spool j made in two parts, the inner onebein g a disk-shaped washer,which is first screwed up tight against the ends of the commutaton bars. The outer part is a plain screw-threaded disk, which, when screwed up to place, as shown, acts as a jam'nut to hold the parts firmly together. The act of tightening up the head or end of the spool gives the bars a spiral twist, as shown in Fig. 6, so that in use the brushes L will overlap the spaces between the bars andprevent sparking.

I will now describe myimproved means for regulating the electric current, which is shown at the left of the field-magnet, Fig. 1. M is a solenoid secured upon a board M', within which is a cone N, to the upper end of which is hinged a bar n, which is fulcrumed upon a stud n. The free end of the bar n bears upon one or other of the contact-buttons o, each of which is in electrical connection with a resistance-coil O, placed in a shunt around the field as the bar is vibrated around its pivot. To the top of the core N is secured one end of a spiral spring P, the opposite end of which is secured to a regulating-screw p, tapped through a bracket p', which is secured above the solenoid. One end of the wire from the field-magnet is connected to the upper contact-button at o, and the opposite end is connected to the bar n at its fulcrum n. The tension of spring P is so regulated that when the current passing is normal the outer end of the bar n will be about midway in the resistance, as shown. Now should the current in the main line be increased from any cause the solenoid M will draw the core N down against the force of the spring P, and by that means shortcircuit part of the variable resistance O, and thus weaken the magnetism and cut down the electro-motive force. In case the current becomes too Weak thc core N is drawn up by the spring P, more resistance is cut into the shunt, and the electromotive force increased.

1. The combination, substantially as specitied, of the armature-shaft, the longitudinallygrooved cylinder E, the thin iron disks F, mounted upon said cylinder', the insulating collars G, and the clamping-collars H to hold the parts together, substantially as specified.

2. The combination of the armatureshaft, the longitudinally-grooved wooden cylinder mounted thereon, the iron disks F, perforated radially and transversely, as shown, the insulating-disks G, and clamping-heads Il for securely holding said core together.

In a dynamo-electric machine, the combination of the armature shaft, the longitudinally-grooved Wooden cylinder mounted thereon, the iron disks F, perforated at f f', the insulating-washers G, the clamping-heads H, notched at their edges, the insulating-pins secured in said notches, and the wire l, wound around said core, substantially as hei-einbefore set forth.

LAWRENCE N. P. POLAND.

Witnesses:

GEO. J. MURRAY, MARY L. MURRAY. 

